I would first make sure that the soil is moist, then gently pull some soil away from the base with my finger, so I can see where the offset joins the mother plant. If the the offset has a fair number of roots, I would carefully separate it from the mother with a sharp knife or pruning shears, snip all of the leaves to 1/2 length, pot it up in fast draining mix. It would like to spend its first few weeks in bright shade, and a light dose of seaweed extract will help it to regenerate its root system.

I would make sure that the soil was moist, then gently pull some soil away from the base with my finger. If the offset has a fair amount of roots, I would pot it up by itself. Otherwise, just cover it back up, and give it another 6 months to a year.
Whoops! my first comment took a while to post, and I thought that I had forgotten to post it!